[DllImport("coredll.dll")]
private static extern int MultiByteToWideChar(
uint CodePage,
uint dwFlags,
string lpMultiByteStr,
int cbMultiByte,
byte[] lpWideCharStr,
int cchWideChar
);
However you have the ability through the System.Text namespace to get a byte
representation of a string in a variety of encodings so you would probably
not need to P/Invoke. What are you trying to achieve?
Peter